Q: Why do I get « Login Return Time is Up »?
A: There might be a bad network configuration or a misconfigured firewall. Also, if you are using NAT / Port Forwarding, please check that the ports are forwarded accordingly – TCP or UDP, not TCP+UDP.

Question: What are the default passwords on DAHUA devices?
Réponse: The default passwords are as same as the username, as in:
admin -> admin
888888 -> 888888
666666 -> 666666 (only DVR/NVR/HCVR local access)